The Hong Kong Monetary Authority (HKMA) said it has received information from "overseas regulatory authorities about possible misconduct by UBS involving submissions for the Hong Kong Interbank Offered Rate and other reference rates in this region".

The regulator said that it had launched an investigation to see if any of UBS's actions had a "material impact."

It is part of a worldwide investigation into the rigging of the Libor rate.

The US Justice Department said also charged Tom Hayes, a British former Tokyo-based trader, and Roger Darin, a Switzerland-based managing director responsible for the bank’s Libor submissions, with conspiracy.